Readily donned, powder-free elastomeric article

ABSTRACT

An elastomeric article such as a glove includes a substrate body made of an styrene-ethylene-butylene-styrene block copolymer, and a donning layer overlying at least one side of the substrate body. The donning layer is formed of 1,2 polybutadiene, preferably syndiotactic  1,2  polybutadiene, or a chlorinated mid block unsaturated block copolymer. Optionally, a surfactant layer is present over the donning layer to further improve the donning characteristics. The surfactant layer is preferably an alkyl dimethylbenzyl quaternary, an alkyl trimethyl quaternary, a dialkyl dimethyl quaternary, sodium lauryl sulfate, or pyridinium chloride.

This application is a continuation in part of pending and allowedapplication Ser. No. 08/604,009, filed Feb. 20, 1996, now U.S. Pat. No.______, for which priority is claimed.

BACKGROUND OF THE INVENTION

This invention relates to elastomeric articles such as gloves, and, moreparticularly, to such elastomeric articles specially treated to makethem easy to slip on.

Highly elastic articles such as surgical and examination gloves havetraditionally been made of natural rubber latex in order to utilize itscombination of good elasticity and strength. However, some persons areallergic to natural rubber latex, and in addition natural rubber latexis susceptible to environmental damage such as ozonation. For manyyears, the only available alternatives to natural rubber latex weresynthetic elastomers which did not produce allergic reactions, but whichalso tended to exhibit insufficient elasticity and strength, as well assusceptibility to ozone degradation in some cases.

An important advance in this area was the development of medical glovesmade of S-EB-S (styrene-ethylene-butylene-styrene) synthetic elastomerblock copolymers, as disclosed in U.S. Pat. Nos. 5,112,900 and5,407,715. Articles such as gloves are readily dip-formed from suchblock copolymers, without the occurrence of pinholes that can resultfrom impurities found in natural rubber latex. The articles havesubstantially the same elastic and strength properties as natural rubberlatex, are hypoallergenic, and are not subject to ozonation damage.Gloves made of S-EB-S block copolymers are available commercially fromTactyl Technologies, Inc., Vista, Calif.

Tightly fitting elastomeric articles such as gloves and condoms, whethermade of natural or synthetic elastomers, can be difficult to don. Theelastomer action of the material of construction, its friction with-theskin of the user, and the perspiration on the body of the user act incombination to make it difficult to slip the article on. To overcomethis problem, it has been conventional practice to apply a powderedlubricant to the surface that is to contact the body of the user, suchas the inside of the glove. As an example, epichloro-hydrin treatedmaize crosslinked starch is a common powder applied to the inside ofelastomeric gloves during manufacture, to permit them to be more readilyslipped onto the hand of the user.

The use of a powdered lubricant on the elastomer is operable, but hasdrawbacks in specific situations such as the case of surgical gloves. Ifsome of the powder escapes from the inside of the glove into thesurgical environment, as for example of the glove is torn during thesurgery, the powder may enter the surgical wound to cause furthercomplications for the patient. The powder may carry infectious agents,or the patient may be allergic to the powder.

Various other techniques are known for use with surgical gloves toimprove their donning characteristics. These techniques include, forexample, manufacturing the glove from a modified latex, using an innerlayer of a hydrophilic polymer, applying a slip coating to the innersurface of the glove, providing lubricating particles on the innersurface of the glove, and other approaches.

While these techniques for producing powder-free gloves are perhapsoperable in their conventional applications, the present inventors havefound that they are not fully satisfactory for use with gloves made ofthe synthetic S-EB-S block copolymers and some other materials ofconstruction. There is, accordingly, a need for an improved approach forproviding a powder-free article such as a glove with acceptable donningcharacteristics. The present invention fulfills this need, and furtherprovides related advantages.

SUMMARY OF THE INVENTION

The present invention provides an elastomeric, powder-free articlehaving excellent donning characteristics. The article is preferably madeusing a substrate of synthetic elastomer that exhibits good elasticityand strength, is hypoallergenic, is resistant to environmentaldegradation, is producible by dip forming, and is otherwise acceptablefor use. These properties are not adversely affected by the treatmentand structure that provide improved donning characteristics, bothinitially and after aging of the article. The treatment for improvingthe donning characteristics is fully compatible with the forming of theunderlying substrate. The approach of the invention is operable with awide variety of substrate materials including, but not limited to, thosemade of natural rubber latex and those made of S-EB-S block co-polymerssuch as those disclosed in U.S. Pat. Nos. 5,112,900 and 5,407,715.

In accordance with one aspect of the invention, an elastomeric articlecomprises a substrate body made of an elastomeric material such asnatural rubber latex or a mid block saturated styrene block copolymersuch as an styrene-ethylene-butylene-styrene block copolymer, and adonning layer overlying at least one side of the substrate body. Thedonning layer comprises 1,2 polybutadiene, preferably syndiotactic 1,2polybutadiene. Optionally, a surfactant-containing layer overlies thedonning layer and comprises a cationic surfactant, or a cationicsurfactant and a silicone antifoam. Operable surfactant-containinglayers comprise an alkyl dimethylbenzyl quaternary, an alkyl trimethylquaternary, a dialkyl dimethyl quaternary, sodium lauryl sulfate, and/orpyridinium chloride. The silicone antifoam is preferably polydimethylsiloxane emulsion.

In accordance with another aspect of the invention, an elastomericarticle comprises a substrate body made of an elastomeric material,preferably a mid block saturated styrene block copolymer such as anstyrene-ethylene-butylene-styrene block copolymer, and a donning layeroverlying at least one side of the substrate body. The donning layercomprises a chlorinated mid block unsaturated block copolymer such as achlorinated styrene diene block copolymer, preferably chlorinatedstyrene-isoprene block copolymer. The styrene-isoprene block copolymerpreferably has a polystyrene block content of from about 10 to about 20percent by weight of the total copolymer weight and an end blockpolystyrene molecular weight of at least about 5,000 grams per mole. Asurfactant-containing layer overlies the donning layer and comprises acationic surfactant, or a cationic surfactant and a silicone antifoam.The cationic surfactant is preferably an alkyl dimethylbenzylquaternary, an alkyl trimethyl quaternary, a dialkyl dimethylquaternary, sodium lauryl sulfate, or pyridinium chloride. The siliconeantifoam is preferably polydimethyl siloxane emulsion.

The elastomeric article is manufactured by preparing the substrate bodymade of an elastomeric material by any operable technique, mostpreferably dip forming. The donning layer is applied to the substratebody by any operable technique, most preferably by dipping the substratebody into a solution of the donning layer polymer, and thereafterchlorinating the donning layer. The surfactant layer is applied over thedonning layer by any operable technique, most preferably by dipping thesubstrate body and overlying donning layer into a solution of thesurfactant.

The elastomeric article of the invention has excellent elastic andstrength properties, is readily manufactured, and can be donned easilywithout the presence of any powder. In the case of the preferred S-EB-Ssubstrate body, the article is hypoallergenic and is resistant toenvironmental degradation such as ozonation. The donning layer does notcrack or peel from the substrate body during storage or service. Otherfeatures and advantages of the present invention will be apparent fromthe following more detailed description of the preferred embodiment,taken in conjunction with the accompanying drawings, which illustrate,by way of example, the principles of the invention. The scope of theinvention is not, however, limited to this preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an elastomeric article made according tothe invention;

FIG. 2A is a sectional view through a first embodiment of the article ofFIG. 1, taken generally along line 2-2;

FIG. 2B is a sectional view through a second embodiment of the articleof FIG. 1, taken generally along line 2-2;

FIG. 3 is a schematic illustration of the microstructure of thestyrene-isoprene-styrene material;

FIG. 4 is a block flow diagram for a preferred method of practicing theinvention; and

FIGS. 5A and 5B are representations of chemical structures, wherein FIG.5A represents 1, 2 polybutadiene, and FIG. 5B represents syndiotactic1,2 polybutadiene.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 depicts an article made in accordance with the invention, in thepreferred case a glove 20 on the hand of a user 22. FIGS. 2A and 2Billustrate the structure of two preferred embodiments of the glove 20.In both embodiments, the glove includes a substrate body 24 having thebasic shape of the article, and a coating 26 on an inside surface 28 ofthe substrate body 24 that is to contact the body of the user 22 duringservice. The coating 26 includes a donning layer 30 overlying,contacting, and bonded to the substrate body 24. The embodiment of FIG.2B further includes a surfactant layer 32, which also may be termed alubricant layer, overlying and contacting the donning layer 30. FIGS. 2Aand 2B are presented to illustrate the positions of the elements, andare not drawn to scale. The surfactant layer 32, for example, istypically at most only a few molecules thick.

The substrate body 24 is made of an elastomeric material, desirablycomprising a synthetic elastomer including at least onestyrene-ethylene-butylene-styrene (S-EB-S) block copolymer, andpreferably a mixture of S-EB-S block copolymers. More preferably, theelastomeric material of the substrate body 24 includes a block copolymercomponent comprising at least two, and most preferably three, S-EB-Sblock copolymers. Each block copolymer has from about 25 to about 35percent by weight of polystyrene blocks. The total mass of S-EB-S blockcopolymers has from about 40 to about 60 percent by weight of a firstS-EB-S block copolymer with a solution viscosity of about 6500 cps at 25percent by weight of copolymer in toluene at 77° F., from about 15 toabout 59 percent by weight of a second S-EB-S block copolymer with asolution viscosity of about 2000 cps in toluene at 10 percent weight ofpolymer in toluene at 77° F., and from about 1 to about 40 percent byweight of a third S-EB-S block copolymer having a solution viscosity ofabout 1600 cps in toluene at 25 percent weight of polymer in toluene at77° F. The most preferred elastomeric material further includes aplasticizer in an amount of from about 30 to about 65 parts by weight ofthe total mass of the S-EB-S block copolymer component. The article isfabricated by dipping a former into a liquid solution of the elastomer asufficient number of times to build up the desired thickness on theformer. This synthetic elastomeric material and the fabrication processare described more fully in U.S. Pat. Nos. 5,112,900 and 5,407,715,whose disclosures are incorporated by reference.

In one embodiment, the donning layer 30 comprises a chlorinated midblock unsaturated styrene-isoprene-styrene (S-I-S) block copolymer. TheS-I-S block copolymer may include tri- or radial-blocks. The S-I-S blockcopolymer preferably has a polystyrene end block content of from about10 to about 20 percent by weight, most preferably from about 15 to about18 percent by weight, of the total weight of the S-I-S block copolymer.If the polystyrene end block content is below about 10 percent byweight, optimum strength properties are not achieved at highertemperatures. If the polystyrene end block content is above about 20percent by weight, the treated surface of the article tends to be toosmooth, promoting blocking and glare of the article, and also tends tostiffen the final article. Too high a polystyrene end block content isparticularly to be avoided when the donning layer is used on adip-formed substrate body. A further reason for selecting a maximumpolystyrene end block content of about 20 percent by weight of the totalS-I-S block copolymer is that this content produces a morphology ofpolystyrene domains 40 dispersed in a continuous polyisoprene matrix 42in the donning layer 30, as illustrated in FIG. 3. This morphologyresults in good bonding of the donning layer 30 to the substrate body24, both initially and after aging, and also imparts good elasticity tothe donning layer so that it can stretch with the elastomer of thesubstrate body 24 without cracking. The donning layer also has goodcrack and peel resistance as a result of its composition and morphology.Polystyrene block contents greater than about 20 percent by weightresult in a more agglomerated structure.

The molecular weight of the polystyrene end blocks is preferably atleast about 5,000 grams per mole. It has been found that S-I-S blockcopolymers having polystyrene end blocks of molecular weight less thanabout 5,000 grams per mole have increased adhesion and blockingtendency, both initially and after heat aging. Blocking is the adhesionor sticking together of adjacent articles and, where present, causes thegloves to be difficult to open for insertion of the hand and also causesneighboring gloves to stick together in a package. A polystyrene endblock molecular weight of more than about 5,000 grams per mole has beenfound to reduce this undesirable blocking, particularly when thesubstrate body is formed by a dip-forming technique.

Examples of suitable mid-block unsaturated S-I-S block copolymersinclude Kraton^(R) D 1107 available from Shell Chemical Co. andVector^(R) 511 and Vector^(R) 4111 available from Dexco. The Vector^(R)4111 product, for example, contains 17.5-19.0 percent by weight styreneend blocks.

The material of the donning layer 30 can also be made of other polymershaving reactive sites which can react with chlorine in the subsequentchlorination procedure. Elastomers having no such sites reactive withchlorine are not operable.

The donning layer 30 of mid block unsaturated S-I-S block copolymer hasa chlorinated surface remote from the surface 28, indicatedschematically at numeral 34 in FIGS. 2A and 2B. The chlorine atoms reactwith the mid-block (unsaturated) polyisoprene, modifying the tackinessof the layer slightly. Other halogens such as bromine or iodine may alsobe used, but are less preferred.

The surfactant layer 32 overlies the donning layer 30 in the embodimentof FIG. 2B. The surfactant layer 32 aids in donning the article when theuser's body is either wet or dry and also reduces the tendency toblocking. The surfactant layer preferably comprises a cationic, ananionic, or a nonionic surfactant, and/or a silicone antifoam. Mostpreferably, the surfactant layer 32 is an alkyl dimethylbenzylquaternary, an alkyl trimethyl quaternary, a dialkyl dimethylquaternary, a pyridinium chloride such as cetyl pyridinium chloride,sodium lauryl sulfate, and/or polydimethyl siloxane emulsion, optionallymixed with silicone such as Dow Corning 365 emulsion or General ElectricAF60. Examples of alkyl dimethylbenzyl quaternaries are steralkoniumchloride and stearyl dimethylbenzyl ammonium chloride, such as thecommercially available Varisoft SDC-85, Ammonyx 4002, Standamul 1002,and Mackernium SDC-85. An example of alkyl trimethyl quaternary isbehentimonium chloride, such as the commercially available VarisoftBT85. Examples of dialkyl dimethyl quaternaries are C18-C22 trimethylammonium metosulfate, such as the commercially available Varisoft BTMS,and disteryldimonium chloride, such as the commercially availableVarisoft TA100.

By way of example, the substrate body 24 in the case of a glove producedby dip forming is preferably from about 0.004 to about 0.012 inchesthick. The donning layer 30 cannot be readily expressed as having athickness, but about 0.15 grams of the mid block unsaturatedstyrene-isoprene (SIS) block copolymer is used per glove. Thechlorinated region 34 and the surfactant layer 32, where present, aremore in the nature of surface treatments. These values are provided byway of illustration and not limitation.

FIG. 4 illustrates the preferred approach for practicing this embodimentof the invention. The substrate body is prepared, preferably by dipforming, numeral 50. The preferred dip forming technique is discussedfully in U.S. Pat. Nos. 5,112,900 and 5,407,715. Briefly, the S-EB-Sblock copolymers are mixed with a plasticizer. The plasticizer ispreferably a mineral oil, which is a refined petroleum paraffinichydrocarbon oil. The preferred mineral oil has a specific gravity of0.87 at 77° F., a viscosity of 170 centistokes at 77° F., and aHirschler molecular weight of 492. The S-EB-S block copolymers arefurnished by the manufacturer as a solid. To form a solution from whicharticles can be dip formed, the S-EB-S block copolymers and the mineraloil plasticizer are dissolved in a mutual solvent, preferably toluene.Toluene solutions of S-EB-S provide minimal viscosities of concentratedsolutions compared to many other solvents. A highly concentratedsolution improves dip-forming process economics by reducing the amountof solvent that must be processed in a solvent recovery operation. TheS-EB-S in toluene solution is a true, stable solution, as distinct froma mixture or an emulsion. The process requires attaining such asolution, as by using a high shear mixer and mixing for a sufficienttime to reach a homogeneous solution. The solution is filtered to removeany fine particulate matter.

To prepare the glove by dip forming, a sufficiently large amount of theS-EB-S elastomer solution is prepared in the manner described and placedinto a dipping tank, at ambient or elevated temperature. A commerciallyavailable former (typically made of aluminum, glass, plastic, orporcelain) in the shape of the desired article is dipped into the tankand removed slowly, leaving a thin, uniform layer of the liquidelastomer solution deposited onto the former, much in the same mannerthat a layer of paint would be deposited upon the former if it weredipped into a container of paint. The former is dried in a stream of airto permit the solvent in the thin elastomeric layer to evaporate, atambient temperature. The dipping procedure is repeated as necessary tobuild up a substrate body of the required thickness.

The substrate body is dipped into a solution of the mid blockunsaturated block copolymer to deposit the block copolymer onto thesurface of the substrate body, numeral 52. The preferred S-I-S mid blockunsaturated block copolymer is dissolved into a solvent such as toluenein a dilute concentration, preferably about 4 percent by weight. Inpractice, the outside of the article is coated, and later turned insideout.

The solvent in which the S-I-S block copolymer is dissolved is removed,numeral 54, preferably by air drying.

The layer of mid block unsaturated block copolymer is chlorinated,numeral 56. Any operable chlorinating approach may be used. A number ofoperable techniques utilized by the inventors are described in thesubsequent examples. The most preferred chlorination procedure is thatdiscussed below in Example 8.

Optionally, the surfactant layer 32 is applied overlying the donninglayer, numeral 58. When this option is used, a solution of the operablesurfactant, such as 0.5 percent aqueous solution of cetyl pyridiniumchloride or sodium lauryl sulfate, is prepared, and the surface of thearticle having the donning layer is contacted to the solution for about15 seconds at ambient temperature.

The following examples illustrate the practice of the invention, butshould not be interpreted as limiting the invention in any respect. Forall of these examples, the substrate body is an S-EB-S dip-formed gloveprepared according to the approach described above and in U.S. Pat. Nos.5,112,900 and 5,407,715. These studies were performed to validate thepowder-free donning approach of the invention, and there was no attemptto optimize the performance of the gloves or to meet commercialstandards.

The following examples are presented to illustrate aspects of thepresent invention, and should not be interpreted as limiting of theinvention in any respect.

EXAMPLE 1

A Glove was dip formed from S-EB-S block copolymer, as described above.While still on the former but after drying, the glove was dipped into a4 percent by weight solution of Vector^(R) 511 S-I-S block copolymer intoluene. The S-I-S solution on the glove was air dried to remove thesolvent. The glove was dipped into a solution of 4905 grams of water, 70grams of sodium hypochlorite (14 percent by weight in water), andsufficient hydrochloric acid to produce a solution having a pH of 2, fora period of about 15 minutes, and dried. The glove was then strippedfrom the former. It showed good dry donning characteristics without theuse of any powder.

EXAMPLE 2

Example 1 was repeated, except that the chlorinating solution contained4050 grams of water, 700 grams of sodium hypochlorite, and 250. grams ofhydrochloric acid, and the immersion time was 1 minute. After drying andremoving from the form, the glove showed good dry donningcharacteristics without the use of any powder.

EXAMPLE 3

Example 1 was repeated for a batch of 20 gloves, for the dip forming andS-I-S coating steps (but not for the chlorinating step, which wasaccomplished by a different approach as described subsequently). Beforestripping the gloves from their forms, dry cornstarch powder wasapplied. The powdered gloves were loaded into a washing machine with11.4 grams of Surfynol TG^(R) mixed into 38 liters of water. The gloveswere run in the washing machine for 15 minutes at low agitation andremoved from the washer. The washer was then filled with a solution of38 liters of clean water, 1994 grams of 7 percent chlorox bleach (2300ppm chlorine), and 460 milliliters of 6N sulfuric acid, the solutionhaving a pH of 2.2 at 18.9° C. The wet gloves were added with the S-I-Scoating on the outside of the gloves and agitated for 15 minutes. Themeasured pH of the solution rose to 2.41 in 5 minutes, 2.64 after 10minutes, and 2.68 after 15 minutes. After 15 minutes, the solution wasneutralized with 180 milliliters of 3N potassium hydroxide to a pH of7.02, and the gloves were further agitated for 15 minutes and removed.The gloves were rinsed with fresh cold water with 5 minutes ofagitation, rinsed again with fresh cold water for 5 minutes ofagitation. The gloves were removed from the washing machine, dried onlow for 40 minutes, inverted, and dried on low for another 10 minutes.The powder-free gloves produced showed good dry donning characteristicswith a slight yellowish color.

EXAMPLE 4

Example 3 was repeated, except that the SIS-containing Vector^(R) 511solution was 3 percent by weight rather than 4 percent by weight as inExample 3. The finished gloves were gamma sterilized in their packagesat 2.5 Mrad dose. Control specimens with the powder coating wereretained, and some of these specimens were also packaged and gammasterilized. Samples of powder-coated and SIS-coated and chlorinatedgloves were aged at 70° C. for 166 hours. Specimens for mechanicaltesting were retained at the various stages. Mechanical testing wasperformed, with the following results: 500% Modulus Tensile StrengthElongation Specimen (MPa) (MPa) (%) Example 4 sterilized 3.14 23.36 942Example 4 3.20 21.94 934 sterilized + aged Powdered and sterilized 3.0525.22 959 Powdered and 3.6 28.19 913 sterilized + aged

EXAMPLE 5

A batch of 8 pairs of gloves were prepared in the manner described inExample 3, for the dip forming and S-I-S coating steps (but not for thechlorinating step, which was accomplished by a different approach asdescribed subsequently). Before stripping the gloves from their forms,precipitate calcium carbonate powder was applied to prevent sticking.The stripped gloves were placed into a washing machine containing a pH2.03 solution of 38 liters of water, 1994 grams of sodium hypochlorite,and 710 milliliters of 6N sulfuric acid. The gloves were agitated in thesolution for 15 minutes, during which time the pH rose from 2.03 to2.26. The solution was then neutralized with 450 milliliters of 3Npotassium hydroxide to a pH of 7.05. The water solution was drained andthe gloves spun in the washer for 3 minutes, rinsed twice with water for3 minutes each, and dried in a drying on low setting for 40 minutes. Thegloves were inverted and dried for an additional 15 minutes. The gloveshad a light yellow color and showed good dry donning characteristicswithout the application of powder. The samples showed very littleblocking on the S-EB-S (substrate body) side, and no blocking on thechlorinated S-I-S (donning layer) side after heat aging at 60° C. for 14hours in the package, under a weight of 50 pairs of gloves.

EXAMPLE 6

A batch of 64 pairs of gloves were prepared in the manner described inExample 5, for the dip forming and S-I-S coating steps (but not for thechlorinating step, which was accomplished by a different approach asdescribed subsequently). The stripped gloves were placed into a washingmachine containing a pH 2.01 solution of 38 liters of water, 2294 gramsof sodium hypochlorite, and 650 milliliters of 6N sulfuric acid. Afterthe gloves were added, the pH rose to 2.31, and sufficient 6N sulfuricacid was added to bring the pH to 2.28. The gloves were agitated in thesolution for 15 minutes. The solution was then neutralized with 500milliliters of 3N potassium hydroxide to a pH of 7.55. The watersolution was drained and the gloves spun in the washer for 3 minutes andrinsed twice with water for 15 minutes each.

Twenty-five pairs of the gloves were thereafter dried at 130° F. for 40minutes, inverted, and dried for another 20 minutes. The gloves showedgood dry donning characteristics and fair wet/damp donningcharacteristics.

Fourteen pairs of the gloves were rinsed in an aqueous solution of 0.25weight percent cetyl pyridinium chloride and 0.05 weight percent DowCorning silicone emulsion DC365, and dried at 130° F. for 40 minutes,inverted, and dried for another 20 minutes. The gloves had wet/dampdonning characteristics superior to the samples that were untreated withthe cetyl pyridinium chloride/silicone emulsion solution.

Twenty-five pairs of the gloves were rinsed in an aqueous solution of0.5 weight percent cetyl pyridinium chloride and 0.1 weight percent DowCorning silicone emulsion DC365, and dried at 130° F. for 40 minutes,inverted, and dried for another 20 minutes. These gloves had good drydonning characteristics, and improved wet donning characteristicscompared to the gloves of the other two groups of this Example 6.However, there was a sensation of a slight soapy residue in the interiorof the gloves.

All samples showed reduced blocking tendencies on the S-EB-S (substratebody) side after 60° C. aging in the package under a weight of 50 pairsof gloves, with the improvement greatest for the gloves treated with thecetyl pyridinium chloride/silicone emulsion solution.

EXAMPLE 7

A batch of 63 pairs of gloves were prepared in the manner described inExample 3, for the dip forming step (but not for the SIS-treatment orchlorinating steps, which were accomplished by a different approach asdescribed subsequently). The S-I-S treatment was performed as in Example3, except that the solution was 4 percent by weight of Vector^(R) 4111in toluene. The samples were dusted with precipitated calcium carbonatebefore stripping them from the formers. The gloves were chlorinated byloading them into a washing machine having a pH 2.01 solution of 38liters of water, 2294 grams of Chlorox^(R) bleach, and 650 millilitersof 6N sulfuric acid. After the gloves were loaded and subjected to mildagitation, the pH rose to 2.31. An additional 75 grams of sulfuric acidwas added to reduce the pH to 2.28. The gloves were agitated for 15minutes, the solution was neutralized to pH 7.15 by adding 500milliliters of 3N potassium hydroxide, the solution was drained, and thegloves were rinsed with water twice for 15 minutes each time.

One set of 21 pairs of gloves, termed group 7-1, were dried at 130° F.for 40 minutes, inverted, and dried for another 20 minutes.

A second set of 21 pairs of gloves, termed group 7-2, were coated ontheir insides with a solution of 1984 grams of water, 10 grams of cetylpyridinium chloride, and 5.7 grams of Dow Corning silicone DC 365 anddried as for the group 8-1 gloves.

A third set of 21 pairs of gloves, termed group 7-3, were rinsed with asolution of 666.7 grams of the solution prepared for the group 7-2gloves diluted with 666.7 grams of water, and dried as for the group 7-1gloves.

All three groups exhibited good dry donning characteristics, and thegloves of groups 7-2 and 7-3 showed good dry, wet, and damp donningcharacteristics.

The gloves of group 7-1, after sterilization, showed a tensile strengthof 23.39 MPa and an elongation at break of 865%. The samples did notshow any significant change in properties after heat aging at 70° C. for166 hours.

The gloves of group 7-3 after aging for 20 minutes in an ozone chamberat about 250 ppm (parts per million) of ozone showed a tensile strengthof 27.79 MPa and an elongation at break of 881%.

All samples showed a residue of less than 2 milligrams per glove whenthe residue was determined by rinsing the gloves with 150 milliliters ofde-ionized water and determining the dried residue after filtrationusing a 3 micron nitrocellulose filter.

In a second embodiment of the invention, the substrate body 24 may be asdescribed for the first embodiment, preferably a synthetic elastomersuch as the S-EB-S block copolymer material described above, whichdescription is incorporated here. The substrate body 24 may also beother natural and synthetic materials, for example, natural rubberlatex, nitrile, isoprene rubber, S-I-S (styrene-isoprene-styrene) blockcopolymer, S-B-S (styrene-polybutydiene-styrene) block copolymer, S-I(styrene-isoprene) block copolymer, S-B (styrene-butadiene) blockcopolymer, or composition blends thereof.

The donning layer 30 comprises 1,2 polybutadiene, whose chemicalstructure is depicted in FIG. 5A. Most preferably, the donning layer 30is syndiotactic 1,2 polybutadiene, whose chemical structure is depictedin FIG. 5B. This donning layer material is chlorinated.

The surfactant layer 32, where used, is the same as described above forthe first embodiment, which description is incorporated here.

The procedure used to prepare the articles is substantially as shown inFIG. 4, whose above description is incorporated here, with the followingchanges and details of the process. The substrate body is dip formedfrom an operable material such as one of the above-listed materials,numeral 50. The substrate is dipped into the donning layer solution,numeral 52. Where the substrate body is the synthetic elastomer, thesubstrate base is dipped into a solution of the 1,2 polybutadiene,preferably the syndiotactic 1,2 polybutadiene. The solution preferablycontains from about 2 percent to about 7 percent (w/w), most preferablyfrom about 3 percent to about 4 percent, of the 1,2 polybutadiene in anoperable solvent, such as toluene. Where the substrate body is thenatural rubber latex, the donning layer material is preferably preparedas an emulsion, by combining a solution of syndiotactic 1,2polybutadiene with an ionic surfactant and water. The syndiotactic 1,2polybutadiene is dissolved in toluene at from about 5 to about 14,preferably about 9, percent by weight. The surfactant mixture is sodiumdioctyl sulfosuccinate in an amount of from about 10 to about 100,preferably 50, PHR (parts per hundred, rubber) in water. Pre-dispersionis achieved by dispersing the surfactant mixture and syndiotactic 1,2polybutadiene solution using a high shear mixer. The pre-dispersion isthen mixed for about 5 minutes in a rotor/stator (such as a Ross XSeries) mixer to generate an average particle size of less than about 1micrometer. The resulting emulsion is filtered and the solvent removedby vacuum distillation. The concentration in the final emulsion isdiluted for application to the glove. The concentration of the emulsionis from about 3 to about 7 percent syndiotactic 1,2 polybutadiene inwater at the time of application. After the solution or emulsion isdeposited onto the substrate base, the solvent is removed, numeral 54.The donning layer is chlorinated, numeral 56, for example by theprocedure discussed below in Example 8.

The surfactant layer is applied, numeral 58, by contacting a solution ofthe surfactant material to the exposed surface of the donning layer. Thesolution preferably contains from about 0.2 percent to about 1.4 percent(w/w), most preferably from about 0.7 percent to about 1 percent, of thealkyl dimethylbenzyl quaternary, alkyl trimethyl quaternary, dialkyldimethyl quaternary, pyridinium chloride, or sodium lauryl sulfate in anoperable solvent, such as water. When the polydimethyl siloxane emulsionis used in combination with the surfactant material, the concentrationis from about 0.08 percent to about 0.12 percent in water.

EXAMPLE 8

Glove formers were dipped into a 1 percent solution of Presto Products“Compata Bag” dissolved in toluene. “Compata Bag” is a commercialproduct comprising syndiotactic 1, 2 polybutadiene mixed with otheringredients including talc, erucamide, steramide. The former with the“Compata Bag” layer was air dried to remove the solvent. The substratematerial of S-EB-S was then applied by overdipping the “Compata Bag”layer with sufficient dips to provide the desired thickness. While stillon the former, the gloves were again dipped into a 1 percent solution of“Compata Bag” dissolved in toluene, and air dried to remove the solvent.Before stripping, calcium carbonate was applied to the outer surface.The gloves were removed from the formers and prepared for chlorination.

A washing machine was filled with 38 liters of water, 1050 millilitersof 7 percent Chlorox™ bleach (1100 parts per million chlorine) and 425milliliters of 20 percent sulfuric acid, the solution having a pH of 2.0at 19.5° C. With the donning surface of the outside, the powdered gloveswere added to the chlorine and acid solution and agitated for 10minutes, during which time the pH rose from 2.01 to 2.08. After 10minutes the solution was neutralized with 60 milliliters of 50 percentpotassium hydroxide to a pH of 7.76, and the agitation was continued foran additional 15 minutes.

The chlorine was neutralized from the solution and the pH buffered tomaintain neutral pH by adding 325 milliliters of 6 percent hydrogenperoxide and 325 milliliters of 10 percent sodium bicarbonate solutionwith a resulting pH of 7.0. The gloves were rinsed with fresh water with15 minutes of agitation, and rinsed again with fresh cold water with 15minutes of agitation. After draining the final rinse water, the gloveswere rinsed and agitated for 5 minutes in an aqueous solution of 1.0weight percent Varisoft BTMS and 0.1 weight percent GE silicone AF60.They were then dried for 60 minutes, reaching a maximum cycletemperature of 123.3° F., then inverted and dried for an additional 40minutes, reaching a maximum cycle temperature of 130.4° F. The resultinggloves exhibited excellent dry donning characteristics and good damp/wetdonning characteristics.

EXAMPLE 9

Example 8 was repeated, but using a 2 percent solution of “Compata Bag”in toluene instead of the 1 percent solution. The powder-free glovesproduced showed excellent dry and damp/wet donning characteristics.

EXAMPLE 10

Example 8 was repeated, but using a 3 percent solution of Presto“Compata Bag” in toluene instead of the 1 percent solution. Thepowder-free gloves produced showed excellent dry and damp/wet donningcharacteristics.

EXAMPLE 11

Example 10 was repeated, using a 3 percent solution of Presto “CompataBag” in toluene. To the solution were added 10 percent calciumcarbonate, 2 percent erucamide, and 2 percent steramide. The resultingpowder-free gloves exhibited very good dry donning characteristics andgood damp/wet donning characteristics.

EXAMPLE 12

Example 10 was repeated, using a 3 percent solution of Presto “CompataBag” in toluene. To the solution were added 20 percentethylmethacrylate, 2 percent erucamide, and 2 percent steramide. Theresulting powder-free gloves exhibited very good dry donningcharacteristics and good damp/wet donning characteristics.

EXAMPLE 13

Examples 8-10 were repeated, using pure syndiotactic 1,2 polybutadienein place of Presto Products “Compata Bag”, which has additionalingredients as discussed above. The resulting gloves exhibited excellentdry and damp/wet donning characteristics. Some typical physicalproperties are set forth in the following table. Tensile UltimateModulus Tensile at 500 percent Ultimate Strength elongation ElongationSpecimen (MPa) (MPa) (percent) Example 13, with 1 percent 21.08 2.76 933syndiotactic 1,2 polybutadiene, sterilized Example 13, with 2 percent21.78 2.79 992 syndiotactic 1,2 polybutadiene, sterilized Example 13,with 3 percent 21.78 2.80 973 syndiotactic 1,2 polybutadiene, sterilizedExample 13, with 1 percent 20.50 2.76 968 syndiotactic 1,2polybutadiene, sterilized and aged Example 13, with 2 percent 21.26 2.60968 syndiotactic 1,2 polybutadiene, sterilized and aged Example 13, with3 percent 19.76 2.72 979 syndiotactic 1,2 polybutadiene, sterilized andaged Powdered S-EB-S, sterilized 25.2 3.05 959 Powdered S-EB-S,sterilized and 28.19 3.6 913 aged

EXAMPLE 14

Example 8 was repeated, using a 2 percent solution of Firestone Diene645 in toluene, instead of the Presto Products “Compata Bag”. FirestoneDiene 645 comprises 1,2 polybutadiene, but not in the syndiotactic form.The resulting powder-free gloves exhibited fair dry donningcharacteristics.

The following examples illustrate the operability of the surfactantmaterials.

EXAMPLE 15

Chlorinated gloves were prepared having an S-EB-S substrate and an S-I-Swash coat as the donning surface. The gloves were rinsed in an aqueousrinse solution of 0.25 percent cetylpyridinium chloride and 0.05 percentDC-365. The resulting gloves showed good damp/wet donningcharacteristics. Tensile strength was, however, reduced after gammairradiation and accelerated aging.

EXAMPLE 16

Example 15 was repeated, but using an aqueous rinse solution of 0.5percent Ammonyx 4002 from Stepan. The resulting gloves showed gooddamp/wet donning characteristics. The tensile strength was retainedafter gamma irradiation and accelerated aging.

EXAMPLE 17

Example 15 was repeated, but using an aqueous rinse solution of 0.2percent Ammonyx 4002, 0.5 percent BTMS from Witco, and 0.1 percentsilicone from DC-365. The resulting gloves showed very good damp/wetdonning characteristics.

EXAMPLE 18

Example 15 was repeated, but using an aqueous rinse solution of 1.0percent BTMS and 0.1 percent silicone from DC-365. The resulting glovesshowed excellent damp/wet donning characteristics. Tensile strength wasretained through all parts of the processing, including gammairradiation sterilization and accelerated aging.

The surfactant may also be applied without using an aqueous solution. Inone alternative approach, the surfactant is applied to a carrier such asa non-woven fabric by melting the surfactant and coating it onto thecarrier material. The surfactant-coated material is placed in the dryerand the surfactant is liberated during the dry cycle.

Although a particular embodiment of the invention has been described indetail for purposes of illustration, various modifications andenhancements may be made without departing from the spirit and scope ofthe invention. Accordingly, the invention is not to be limited except asby the appended claims.

1. An elastomeric article, comprising: a substrate body made of an elastomeric material; and a donning layer overlying at least one side of the substrate body, the donning layer comprising 1,2 polybutadiene.
 2. The elastomeric article of claim 1, wherein the substrate body has the form of a glove having an inside surface, and the donning layer overlies the inside surface of the glove.
 3. The elastomeric article of claim 1, wherein the elastomeric material of the substrate body comprises a mid block saturated styrene block copolymer.
 4. The elastomeric article of claim 1, wherein the elastomeric material of the substrate body comprises a styrene-ethylene-butylene-styrene block copolymer.
 5. The elastomeric article of claim 1, wherein the elastomeric material of the substrate body is selected from the group consisting of natural rubber latex, nitrile, isoprene rubber, styrene-isoprene-styrene block copolymer, styrene-polybutydiene-styrene block copolymer, styrene-isoprene block copolymer, styrene-butadiene block copolymer, and composition blends thereof.
 6. The elastomeric article of claim 1, further including a surfactant layer overlying the donning layer.
 7. The elastomeric article of claim 1, further including a surfactant layer overlying the donning layer, the surfactant layer comprising a surfactant selected from the group consisting of a cationic surfactant, and a cationic surfactant and a silicone antifoam.
 8. The elastomeric article of claim 1, further including a surfactant layer overlying the donning layer, the surfactant layer comprising a surfactant selected from the group consisting of an alkyl dimethylbenzyl quaternary, an alkyl trimethyl quaternary, a dialkyl dimethyl quaternary, a pyridinium chloride, sodium lauryl sulfate, and polydimethyl siloxane emulsion.
 9. The elastomeric article of claim 1, wherein the donning layer polymer comprises syndiotactic 1,2 polybutadiene.
 10. An elastomeric article, comprising: a substrate body made of an elastomeric material; a donning layer overlying at least one side of the substrate body, the donning layer comprising a chlorinated mid block unsaturated block copolymer; and a surfactant layer overlying the donning layer, the surfactant layer comprising a surfactant selected from the group consisting of a cationic surfactant, and a cationic surfactant and a silicone antifoam.
 11. The elastomeric article of claim 10, wherein the cationic surfactant is selected from the group consisting of an alkyl dimethylbenzyl quaternary, an alkyl trimethyl quaternary, a dialkyl dimethyl quaternary, a pyridinium chloride, and sodium lauryl sulfate.
 12. The elastomeric material of claim 11, wherein the surfactant layer further includes a silicone.
 13. The elastomeric article of claim 10, wherein the silicone antifoam is polydimethyl siloxane emulsion. 